Preparation method of Co-MOF derivative catalyst and application of Co-MOF derivative catalyst in catalytic hydrogenation of high-concentration furfural
A carbon-coated Co@C catalyst was prepared by derivatizing Co-MOF materials, which solved the side reaction problem in the catalytic hydrogenation of furfural and achieved high-yield production of cyclopentanone and cyclopentanol at high concentrations. The catalyst is stable and recyclable, making it suitable for industrial applications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAMEN UNIV
- Filing Date
- 2026-03-16
- Publication Date
- 2026-05-19
AI Technical Summary
During the catalytic hydrogenation of furfural, side reactions such as resinification and aldol condensation are prone to occur under high concentration or high temperature conditions, leading to catalyst deactivation and decreased product selectivity, which has become a bottleneck restricting its industrial application.
A carbon-coated Co@C catalyst was prepared by derivatizing Co-MOF materials. The core-shell structure was formed by high-temperature calcination. Combined with co-solvents such as ethanol, the hydrogenation reaction of high-concentration furfural was achieved, avoiding the occurrence of side reactions.
Achieving high yields of 84.3 mol% cyclopentanol and 15.1 mol% cyclopentanone at low concentrations, while maintaining high quality yields at high concentrations, the catalyst is recyclable, reducing costs and making it suitable for industrial applications.
Smart Images
Figure CN122057510A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of catalysts, specifically relating to a method for preparing a Co-MOF-derived catalyst and its application in the catalytic hydrogenation of high-concentration furfural. Background Technology
[0002] Developing and utilizing biomass resources to gradually replace traditional fossil resources is an important way to meet the needs of human society for clean production. Furfural (FFA), as a key platform compound, is mainly extracted from lignocellulose in agricultural byproducts such as corn cobs and straw, and is obtained through the hydrolysis of hemicellulose catalyzed by dilute acid. (Luxin Zhang et al., Transformation of corncob into furfural by a bifunctional solid acid catalyst, Bioresource Technology, 276, 2019, 60-64.) Currently, furfural has achieved large-scale industrial production and is widely used in fine chemicals, polyesters, petroleum refining, pharmaceuticals, and pesticides. Its aldehyde group and furan ring in its molecular structure endow it with high reactivity, enabling it to be further synthesized into high-value-added chemicals and high-density oxygen-containing fuels, including various alcohols, ketones, and diols, through reactions such as hydrogenation, ring-opening rearrangement, condensation, and oxidation. (Ye Tian et al., Green and efficient selective hydrogenation of furfural to furfuryl alcohol over hybrid CoO x / Nb2O5 nanocatalyst in water, Molecular Catalysis, 2023, 538, 112981.; A layered nanosheet composite material and its method for catalytic hydrogenation and hydrolysis of furfural to prepare furfuryl alcohol and pentanediol: CN117619389A; A method for the hydrogenation rearrangement of furfural to prepare cyclopentanone and cyclopentanol: CN113786837A) Developing downstream products of furfural not only helps to enhance its economic value and extend the industrial chain, but also has positive significance for related industries to reduce carbon emissions and promote the realization of "dual carbon" goals.
[0003] Currently, due to the relatively reactive functional groups in furfural molecules, there is a lack of effective means to completely suppress side reactions such as resinification and aldol condensation under high concentration or high temperature conditions during catalytic hydrogenation. These problems not only cause feedstock loss but also lead to rapid catalyst deactivation and a significant decrease in product selectivity, becoming key bottlenecks restricting the industrial application of furfural catalytic hydrogenation. Despite these challenges, the price of downstream furfural products remains high due to limited fossil resource supply, thus furfural catalytic hydrogenation still possesses significant industrial development potential and economic prospects. Integrating traditional thermocatalysis with novel catalytic systems, exploring new reaction pathways, and constructing economically feasible, green, and sustainable new reaction systems are becoming key research directions driving the development of this field. Summary of the Invention
[0004] The present invention addresses existing technical challenges by providing a method for preparing a carbon-coated Co@C catalyst derived from Co-MOF materials and its application. This catalyst achieves yields of 84.3 mol% cyclopentanol and 15.1 mol% cyclopentanone in 3 hours at a low concentration of 2 wt%, and can then be used for the hydrogenation of furfural at a high concentration of 10 wt% to prepare cyclopentanone or cyclopentanol. The catalyst preparation method is simple, possesses a stable core-shell structure, strong hydrogenation activity, and recyclability. The catalyst itself is magnetic, and recovery is straightforward. Using ethanol as a co-solvent, the catalytic hydrogenation of high-concentration furfural in an aqueous phase to prepare cyclopentanone or cyclopentanol can be achieved with excellent catalytic performance, maintaining high yields even in scale-up experiments, demonstrating industrial potential.
[0005] This invention provides a method for preparing a Co@C catalyst derived from Co-MOF materials and coated with carbon, comprising the following steps:
[0006] (1) Preparation of Co-MOF materials:
[0007] Cobalt nitrate hexahydrate and terephthalic acid are dissolved in N,N-dimethylformamide solution and stirred until completely dissolved; the solution is then added to a hydrothermal reaction vessel and heated to react, yielding solid Co-MOF material; preferably, stirring is performed for 30 minutes.
[0008] (2) Preparation of Co@C catalyst:
[0009] The Co-MOF material from step (1) is dried to remove the remaining N,N-dimethylformamide. The treated solid is placed in a reactor and heated for carbonization and reduction under a reducing atmosphere. After cooling to room temperature, it is passivated to obtain a carbon-coated Co@C catalyst. Preferably, the Co-MOF material from step (1) is filtered and then dried in a vacuum drying oven. Preferably, the reactor is a tube furnace.
[0010] (3) Preferably, the Co@C catalyst is used to catalyze the hydrogenation reaction of high-concentration furfural; the high concentration means that the concentration of furfural is 8-18%; preferably 9-15%; more preferably 10%;
[0011] Preferably, the hydrogenation reaction step for high-concentration furfural is as follows:
[0012] First, furfural and co-solvent are mixed evenly, then an appropriate amount of catalyst powder is added, and finally deionized water is added to prevent furfural from forming insoluble particles in the water and adhering to the inner wall of the reactor. After sealing the reactor, low-pressure nitrogen is continuously introduced to purge the inside of the reactor to remove the remaining air, and then pure hydrogen is introduced. The reactor needs to be heated in stages according to a programmed procedure to avoid side reactions such as furfural self-polymerization caused by overheating in one go. After the reaction is completed, the waste gas is slowly discharged and treated with alkaline solution after the temperature has cooled to room temperature. Preferably, the staged heating refers to the temperature being controlled in stages at 120 ℃, 140 ℃, and 160 ℃.
[0013] In the method described above, in step (1), the mass ratio of cobalt nitrate hexahydrate, terephthalic acid, and N,N-dimethylformamide is (0.25-2.0) g: (0.15-1.2) g: (25-100) mL; preferably (0.5-2.0) g: (0.3-1.2) g: (50-100) mL; more preferably (1.0-1.5) g: (0.6-0.9) g: (60-70) mL; and even more preferably 0.5 g: 0.3 g: 50 mL.
[0014] As described above, in step (1), the heating reaction is carried out in an oven at (140-170) °C for (8-12) h; preferably, the heating temperature is 160 °C and the heating time is 10 h.
[0015] As described above, in step (1), after the heating reaction, the material is further cooled to room temperature and then filtered. The filtered solid is then vacuum dried or oven-dried to obtain a sheet-like purple solid Co-MOF material.
[0016] In the method described above, in step (2), the reducing atmosphere is N2 containing 10% H2, and the reduction conditions are reduction at (400-600)℃ for (1-2) hours, preferably reduction at 500℃ for 2 hours.
[0017] In the method described above, in step (2), after cooling to room temperature, it is necessary to switch the atmosphere to N2 passivation containing 0.5-2% O2 for (1-2) hours, preferably 1% for 2 hours.
[0018] The present invention also provides Co@C catalysts prepared by any of the methods described above.
[0019] This invention also provides the application of the Co@C catalyst described above in the catalytic hydrogenation of high-concentration furfural. Different co-solvents are used to increase the solubility of furfural in the reaction solution and reduce the formation of byproducts in the reaction. The Co@C catalyst is used to catalyze the hydrogenation of high-concentration furfural to prepare the corresponding aldehydes and alcohols. Specifically, different co-solvents are added to the reaction solution to uniformly disperse furfural in the solution to form a homogeneous phase, thereby increasing the reaction contact sites. The co-solvents are non-toxic, environmentally friendly, recyclable, and suitable for industrial application. The aldehydes and alcohols are cyclopentanone and cyclopentanol. The co-solvent is any one of methanol, ethanol, tetrahydrofuran, acetonitrile, and N,N-dimethylformamide, preferably ethanol. Preferably, the Co@C catalyst is applied to the hydrogenation of furfural at high concentrations to prepare cyclopentanone and cyclopentanol, where the high concentration is 8-18% furfural; preferably 9-15%; more preferably 10%, and even more preferably 8.3%.
[0020] As described above, with the addition of ethanol as a co-solvent, the Co@C catalyst can achieve a high total mass yield at high substrate concentrations.
[0021] As described above, the specific catalytic steps are as follows: furfural and ethanol are placed in a reactor and stirred until they are miscible. Then, Co@C catalyst is added and stirred to disperse the solid particles. Finally, deionized water is added, and the reactor is sealed. After purging excess air with low-pressure nitrogen, hydrogen is introduced. The reaction is carried out by programmed segmented heating to the target temperature. After the reaction is completed, the mixture is cooled to obtain cyclopentanone and cyclopentanol. Preferably, the segmented heating refers to the temperature being controlled in segments of 120 °C, 140 °C, and 160 °C.
[0022] Compared with the prior art, the present invention has the following advantages and effects:
[0023] 1. This invention uses Co-MOF as a precursor to derive a Co@C carbon-coated catalyst through high-temperature calcination. The preparation method is simple and low-cost. In this catalyst, Co species are uniformly dispersed, have high crystallinity, and exhibit a distinct carbon-coated core-shell structure. The added co-solvent significantly improves the overall product yield, and both the co-solvent ethanol and the catalyst can be directly separated and recovered for reuse, further reducing reaction costs.
[0024] 2. In the application of this invention, furfural raw material is a cheap agricultural by-product, realizing the high-value utilization of biomass resources and reducing the impact of by-product generation on the reaction during the conversion process.
[0025] 3. Compared with existing hydrogenation catalysts, the advantages of this invention are that it can achieve extremely high concentrations of furfural hydrogenation, and is not limited to the conventional low-concentration furfural hydrogenation to prepare cyclopentanone and cyclopentanol. High product yields can still be obtained in scaled-up reactions, which is beneficial for its industrial application. Attached Figure Description
[0026] Figure 1 Example 1: Catalyst preparation flowchart.
[0027] Figure 2 Scanning electron microscope image and elemental EDS spectrum of the Co@C catalyst prepared in Example 1.
[0028] Figure 3 Transmission electron microscope image and elemental EDS spectrum of Example 1.
[0029] Figure 4 Example 1: X-ray diffraction (XRD) patterns of the catalyst before and after the cyclic test.
[0030] Figure 5 Example 1: Scanning electron microscope (SEM) images of the catalyst before and after the cyclic test. Detailed Implementation
[0031] The technical solution of the present invention will now be described in detail with reference to specific embodiments and accompanying drawings.
[0032] Unless otherwise specified, all reagents and instruments used in the following examples are commercially available products. Specific implementation examples are as follows:
[0033] Example 1: Preparation of Co-MOF-derived carbon-coated Co@C catalyst
[0034] Use such as Figure 1 The catalyst preparation process shown in the figure is specifically prepared as follows:
[0035] Weigh out 0.5 g of cobalt nitrate hexahydrate and 0.3 g of terephthalic acid, dissolve them in 50 mL of N,N-dimethylformamide solvent, and stir until homogeneous;
[0036] The uniformly dissolved solution was transferred to a 50 mL hydrothermal reactor lined with polytetrafluoroethylene and kept in an oven at 160 °C for 10 h. After the reaction was completed, the solution was cooled to room temperature, and the resulting solid was filtered and dried to obtain purple flake-like Co-MOF material.
[0037] The obtained Co-MOF material was transferred to a tube furnace and calcined at 500 °C at a rate of 5 °C / min in a reducing atmosphere containing 10% H2 and N2, and held for 2 h. After the calcination, the material was naturally cooled to room temperature and then passivated in an atmosphere containing 1% O2 and N2 for 2 h to obtain a carbon-coated Co@C catalyst.
[0038] The Co@C catalyst prepared in Example 1 was analyzed and characterized as follows:
[0039] Figure 2These are SEM (Scanning Electron Microscopy) images and elemental EDS (Energy Dispersive Spectroscopy) spectra of the Co@C catalyst. It can be clearly seen that the prepared catalyst exhibits a micron-sized clustered particle structure, and the Co element is uniformly dispersed within the catalyst.
[0040] Figure 3 These are transmission electron microscopy (TEM) images and elemental EDS spectra of the Co@C catalyst. It is clearly visible that the Co metal in this catalyst mainly exhibits (111) and (200) crystal planes, with an interplanar spacing of approximately 0.198 nm. The outer layer is covered by 10-12 layers of graphitic carbon, with a thickness of approximately 3.641 nm, demonstrating a core-shell structure. In the EDS spectra, a small portion of Co shows oxidation, and the carbon distribution is concentrated around the Co metal, indicating good dispersion.
[0041] Figure 4 This is the X-ray diffraction (XRD) pattern of the Co@C catalyst. Under a reducing atmosphere at 500 °C, Co species are reduced to Co. 0 2θ = 44.2 °, 51.5 °, and 75.8 ° correspond to the (111), (200), and (220) crystal planes, respectively (PDF#15-0806). The catalyst has a high degree of crystallinity, which may be the reason for its high catalytic activity.
[0042] Examples 2-8
[0043] The Co@C catalyst prepared in Example 1 was used for the catalytic hydrogenation of high-concentration furfural to prepare cyclopentanone and cyclopentanol. The specific steps are as follows:
[0044] 0.1 g of Co@C catalyst, 1.0 g of furfural, 2 mL of co-solvent, and 10 mL of deionized water were added to a high-pressure reactor, which was then purged with 3 MPa of hydrogen gas and magnetically stirred at 600 rpm until analysis was performed by gas chromatography (Agilent-7890A). Examples 2-7 show that the type of co-solvent has a significant impact on the mass yield of the target products cyclopentanone and cyclopentanol, with anhydrous ethanol as the co-solvent yielding the highest total mass yield (63.6 wt%) (see Table 1).
[0045] Table 1 Effect of cosolvent on yield
[0046]
[0047] Examples 8-13
[0048] Ethanol, as used in Example 3, was employed as the co-solvent in this reaction. The reaction temperature also affects the catalytic hydrogenation of furfural; temperature control required a segmented temperature program (120 °C, 140 °C, 160 °C) to prevent overheating from negatively impacting the reaction. As the temperature increased, the product yield initially increased and then decreased, possibly due to over-reaction and the generation of byproducts. 160 °C was the optimal temperature for the preparation of cyclopentanone and cyclopentanol, and will be used as a condition for further investigation (see Table 2).
[0049] Table 2 Effect of reaction temperature on yield
[0050]
[0051] Examples 14-17
[0052] Experimental data show that higher hydrogen pressure promotes the hydrogenation catalytic reaction, significantly increasing the overall product yield. It can be seen that the yield of cyclopentanone initially decreases, while the yield of cyclopentanol increases with increasing hydrogen pressure, consistent with the observation that cyclopentanol is a subsequent hydrogenation product of cyclopentanone. This may be related to the solubility of hydrogen in solution; the highest overall product yield is observed at a hydrogen pressure of 3 MPa (see Table 3).
[0053] Table 3 Effect of hydrogen pressure on yield
[0054]
[0055] Examples 18-22
[0056] Reaction time has a significant impact on this reaction. As can be seen from Examples 18-22, the yield of cyclopentanone shows a trend of first increasing and then decreasing with increasing reaction time, while the yield of cyclopentanol continuously increases. This is consistent with the result that cyclopentanol is a product of the subsequent hydrogenation of cyclopentanone. The yield of cyclopentanol is the highest at a reaction time of 5 h (see Table 4).
[0057] Table 4 Effect of reaction time on yield
[0058]
[0059] Examples 23-27
[0060] The Co@C catalyst prepared in Example 1 exhibits good cycling stability. Examples 23-27 show the mass yields of cyclopentanone and cyclopentanol after 10 cycles of this catalyst. After 5 cycles, the total yield can still be maintained at around 50 wt%. In the 10th cycle, the total yield drops significantly and falls below 50 wt% (see Table 5).
[0061] Figure 4This is the X-ray diffraction (XRD) pattern of the Co@C catalyst after 10 cycles. Comparison with the catalyst before the cycles shows no significant change in the Co species; Co is still present. 0 Characteristic diffraction peaks.
[0062] Figure 5 This is a scanning electron microscope (SEM) image of the Co@C catalyst after 10 cycles of the experiment. Before the reaction, the catalyst exhibited a relatively dispersed particle and cluster morphology. After the reaction, it formed a flocculent cluster morphology with less dispersed particles.
[0063] Table 5. Effect of Number of Cycles on Yield
[0064]
[0065] Examples 28-31
[0066] Examples 28-31 are scale-up experiments of the catalyst at a substrate content of 4 wt% to verify its industrial feasibility. The reaction was carried out in a 5 L high-pressure stainless steel reactor, and the temperature was increased strictly according to a segmented program (120 ℃, 140 ℃, 160 ℃). After the reaction, the waste gas was slowly discharged and treated with alkaline solution after cooling to room temperature. It can be seen that in multiple experiments by changing the hydrogen pressure, the total mass yield of cyclopentanone and cyclopentanol can be maintained in the range of 50-55 wt%. Furthermore, the cosolvent is environmentally friendly and recyclable, and the catalyst can be recovered after cleaning, further demonstrating its potential for industrial application (see Table 6).
[0067] Table 6 Effect of Hydrogen Pressure on Yield
[0068]
[0069] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the specification should still fall within the scope of the present invention.
Claims
1. A method for preparing a Co-MOF material-derived carbon-coated Co@C catalyst, characterized in that, Includes the following steps: (1) Preparation of Co-MOF materials: Cobalt nitrate hexahydrate and terephthalic acid are dissolved in N,N-dimethylformamide solution and stirred until completely dissolved; the solution is then added to a hydrothermal reaction vessel and heated to react, yielding solid Co-MOF material; preferably, stirring is performed for 30 minutes. (2) Preparation of Co@C catalyst: The Co-MOF material from step (1) is dried to remove the remaining N,N-dimethylformamide. The treated solid is placed in a reactor and heated for carbonization and reduction under a reducing atmosphere. After cooling to room temperature, it is passivated to obtain a carbon-coated Co@C catalyst. Preferably, the Co-MOF material from step (1) is filtered and then dried in a vacuum drying oven. Preferably, the reactor is a tube furnace. (3) Preferably, the Co@C catalyst is used to catalyze the hydrogenation reaction of high-concentration furfural; the high concentration means that the concentration of furfural is 8-18%; preferably 9-15%; more preferably 10%; Preferably, the hydrogenation reaction step for high-concentration furfural is as follows: First, furfural and co-solvent are mixed evenly, then an appropriate amount of catalyst powder is added, and finally deionized water is added to prevent furfural from forming insoluble particles in the water and adhering to the inner wall of the reactor. After sealing the reactor, low-pressure nitrogen is continuously introduced to purge the inside of the reactor to remove the remaining air, and then pure hydrogen is introduced. The reactor needs to be heated in stages according to a programmed procedure to avoid side reactions such as furfural self-polymerization caused by overheating in one go. After the reaction is completed, the waste gas is slowly discharged and treated with alkaline solution after the temperature has cooled to room temperature. Preferably, the staged heating refers to the temperature being controlled in stages at 120 ℃, 140 ℃, and 160 ℃.
2. The method as described in claim 1, characterized in that, In step (1), the mass ratio of cobalt nitrate hexahydrate, terephthalic acid, and N,N-dimethylformamide is (0.25-2.0) g: (0.15-1.2) g: (25-100) mL; preferably (0.5-2.0) g: (0.3-1.2) g: (50-100) mL; more preferably (1.0-1.5) g: (0.6-0.9) g: (60-70) mL; and even more preferably 0.5 g: 0.3 g: 50 mL.
3. The method as described in claim 1, characterized in that, In step (1), the heating reaction is carried out in an oven at (140-170)℃ for (8-12) hours; preferably, the heating temperature is 160℃ and the heating time is 10 hours.
4. The method as described in claim 1, characterized in that, In step (1), after the heating reaction, the material is further cooled to room temperature and then filtered. The filtered solid is then vacuum dried or oven-dried to obtain a sheet-like purple solid Co-MOF material.
5. The method as described in claim 1, characterized in that, In step (2), the reducing atmosphere is N2 containing 10% H2, and the reduction conditions are reduction at (400-600)℃ for (1-2) hours, preferably reduction at 500℃ for 2 hours.
6. The method as described in claim 1, characterized in that, In step (2), after cooling to room temperature, the atmosphere needs to be switched to N2 passivation containing 0.5-2% O2 for (1-2) hours, preferably 1% for 2 hours.
7. The Co@C catalyst prepared by any one of claims 1-6.
8. The application of the Co@C catalyst according to claim 7 in the catalytic hydrogenation of high-concentration furfural, characterized in that, Different co-solvents are used to increase the solubility of furfural in the reaction solution and reduce the formation of by-products in the reaction. The Co@C catalyst is used to catalyze the hydrogenation of high-concentration furfural to prepare corresponding aldehydes and alcohols. Specifically, different co-solvents are added to the reaction solution to uniformly disperse furfural in the solution to form a homogeneous phase, thereby increasing the reaction contact sites. The co-solvents are non-toxic, environmentally friendly, recyclable, and suitable for industrial application. The aldehydes and alcohols are cyclopentanone and cyclopentanol. The co-solvent is any one of methanol, ethanol, tetrahydrofuran, acetonitrile, and N,N-dimethylformamide, preferably ethanol. Preferably, the Co@C catalyst is used to hydrogenate furfural at high concentrations to prepare cyclopentanone and cyclopentanol, where the high concentration is 8-18% furfural; preferably 9-15%; more preferably 10%; and even more preferably 8.33%.
9. The application as described in claim 8, characterized in that, With the addition of ethanol as a co-solvent, the Co@C catalyst can achieve a high total mass yield at high substrate concentrations.
10. The application as described in claim 9, characterized in that, The specific steps of the catalysis are as follows: furfural and ethanol are placed in a reactor and stirred to dissolve them. Then, Co@C catalyst is added and stirred to disperse the solid particles. Finally, deionized water is added and the reactor is sealed. After purging excess air with low-pressure nitrogen, hydrogen is introduced. The reaction is carried out by programmed segmented heating to the target temperature. After the reaction is completed, the mixture is cooled to obtain cyclopentanone and cyclopentanol. Preferably, the segmented heating refers to the temperature being controlled in segments of 120℃, 140℃, and 160℃.